Granted. But they didn't turn out to be wrong for non-reductionist reasons; indeed, they were proven wrong within the context of reductionism, which might be even better proof of the usefulness of reductionism than the ideas it has gotten right.

ETA: I don't think reductionism is right; I don't think the concept of "right" can reasonably apply to reductionism, although certainly the concept of "wrong" could. It is a model of the universe, and one which is, at least with the present evidence, isomorphic with any accurate model of the universe.